Innate immunity, malaria and Burikitt’s lymphoma Michele Bernasconi, PhD University Children’s Hospital Experimental Infectious Diseases and Cancer Research August Forel Strasse 1 CH-8008 Zurich BIO

Innate immunity ↔ Adaptive immunity

Innate ( Nonspecific ) Immunity - The term, innate immunity, refers to the basic resistance to disease that a species possesses - the first line of defense against infection. The characteristics of the innate immune response include the following: Responses are Broad-Spectrum (non-specific) There is no memory or lasting protective immunity There is a limited repertoire of recognition molecules The responses are phylogenetically ancient Potential pathogens are encountered routinely, but only rarely cause disease. The vast majority of microorganisms are destroyed within minutes or hours by innate defenses. The acquired specific immune response comes into play only if these innate defenses are breached.

Cells of the innate immune response Mast cells Phagocytes Macrophages Neutrophils Dendritic cells Natural killer cells γδ T cells B cells

Receptors involved

Receptors involved (adaptive imm.)

Toll-like receptors Two distinct pathways control the inducible synthesis of antimicrobial peptides in Drosophila adult flies. The Toll receptor is activated by the cysteine-knot growth factor Spaetzle (Spz). The activated Toll receptor triggers phosphorylation of the inhibitory protein Cactus though the intermediates Tube and Pelle. Phosphorylated Cactus is degraded by the proteasome, thus allowing nuclear translocation of the transcription factor DIF, which induces synthesis of the antifungal peptide drosomycin. The antibacterial peptide diptericin is induced by a distinct pathway in which a putative membrane receptor activates a signaling complex comprising the Drosophila homologs of IKKβ and IKKγ (encoded by the genes ird5 and kenny, respectively). This complex induces phosphorylation and cleavage of Relish. Upon nuclear translocation, the Rel domain from Relish activates synthesis of diptericin. The caspase Dredd is also required for the induction of the antibacterial peptide genes. Note that it is not yet known whether Spaetzle directly interacts with Toll. Abbreviations: DD, death domain; KD, kinase domain; IL, interleukin; TIR, Toll/IL-1 receptor homology domain.

Toll-like receptors Chiron, D., I. Bekeredjian-Ding, et al. (2008). "Toll-like receptors: lessons to learn from normal and malignant human B cells." Blood.

Toll-like receptors - signaling

Malaria Plasodium vivax or falciparum

Malaria Plasodium vivax or falciparum

Burkitt lymphoma B cell lymphoma Reciprocal translocation Ig-enhancers and chr 8  c-myc: similar to myelocytomatosis viral oncogene (v-myc) Taub R, Morton C, Lenoir G, et al. Translocation of the c-myc gene into the immunoglobulin heavy chain locus in human Burkitt lymphoma and murine plasmacytoma cells. Proc Natl Acad Sci USA 1982;79:

Burkitt lymphoma 1956 Denis Burkitt 1964 Epstein and Barr identify virus Endemic Burkitt's lymphoma: a polymicrobial disease? Rosemary Rochford, Martin J. Cannon & Ann M. Moormann Nature Reviews Microbiology 3, (February 2005)

Burkitt lymphoma Endemic BL & endemic malaria

Malaria activate innate immune system Malaria pigment hemozoin activates TLR9 J Exp Med (2005) 201: Toll-like receptor 9 mediates innate immune activation by the malaria pigment hemozoin. C Coban, KJ Ishii, T Kawai, H Hemmi, S Sato, S Uematsu, M Yamamoto, O Takeuchi, S Itagaki, N Kumar, T Horii, S Akira C CobanKJ IshiiT KawaiH HemmiS SatoS UematsuM YamamotoO TakeuchiS ItagakiN KumarT HoriiS Akira

Malaria activate innate immune system

CIDR1a: cystein-rich inter-domain region 1a of the P. falciparum erythrocyte membraneprotein 1 (PfEMP1) RBCs or CIDR1a bind to EBV positive Burkitt lymphoma cells (memory B cell) and activate proliferation

Malaria activate innate immune system CIDR1a: cystein-rich inter-domain region 1a of the P. falciparum erythrocyte membraneprotein 1 (PfEMP1) RBCs or CIDR1a bind to EBV positive Burkitt lymphoma cells (memory B cell) and activate proliferation

TLR expression and function during normal B cell differentiation and in B cell malignancies. Chiron, D., I. Bekeredjian-Ding, et al. (2008). "Toll-like receptors: lessons to learn from normal and malignant human B cells." Blood.

Further reading Reviews Chiron, D., I. Bekeredjian-Ding, et al. (2008). "Toll-like receptors: lessons to learn from normal and malignant human B cells." Blood. Coban, C., K. J. Ishii, et al. (2007). "Manipulation of host innate immune responses by the malaria parasite." Trends in microbiology 15(6): Krieg, A. M. (2007). "Development of TLR9 agonists for cancer therapy." The Journal of clinical investigation 117(5): Original articles Ewald, S. E., B. L. Lee, et al. (2008). "The ectodomain of Toll-like receptor 9 is cleaved to generate a functional receptor." Nature 456(7222): Chaturvedi, A., D. Dorward, et al. (2008). "The B cell receptor governs the subcellular location of Toll-like receptor 9 leading to hyperresponses to DNA- containing antigens." Immunity 28(6): Chene, A., D. Donati, et al. (2007). "A molecular link between malaria and Epstein-Barr virus reactivation." PLoS pathogens 3(6): e80. Coban, C., K. J. Ishii, et al. (2005). "Toll-like receptor 9 mediates innate immune activation by the malaria pigment hemozoin." J Exp Med 201(1):

Akata cells Sporadic Burkitt's lymphoma cell line c-myc translocation EBV positive EBV can be reactivated by IgG cross-linking Model system to study EBV reactivation to lytic infection Model system to study innate immunity and EBV?

qPCR / Real time quantitative PCR Quantitative analysis of gene expression

qPCR / Real time quantitative PCR Quantitative analysis of gene expression

Quantitative analysis of TLR9 expression in Akata cells mRNA from Akata cells stimulated with different cytokines Retro-transcription mRNA → cDNA PCR with TaqMan probes  TLR9  GAPDH (reference) Data analysis